The race for the Democratic presidential nomination is gathering pace. 

The first debates will be held next month in Miami, even though the Iowa caucuses will not take place until February 2020.

The field grew to 24 last week when New York City Mayor Bill de BlasioBill de BlasioTrump hits Biden for 1994 crime bill support De Blasio hits Biden on crime bill: ‘A huge mistake’ Whip list: Who’s clinched a spot in the 2020 Democratic debates MORE announced his candidacy.

Who are the top contenders?

1. Former Vice President Joe BidenJoe BidenTrump hits Biden for 1994 crime bill support Will top 2020 Democrats make ending war in Afghanistan a defining issue or an afterthought? Nevada emerges as wild card in 2020 Democratic race MORE

Biden has surprised skeptics with the extent of his early strength. 

His rallies have been largely gaffe-free, his initial fundraising totals — $6.3 million in his first 24 hours — have been formidable and he has vaulted to a big polling lead.

In four major recent polls — from Monmouth University, Quinnipiac University, Morning Consult and Fox News — Biden held a greater than two-to-one lead over his nearest challenger, Sen. Bernie SandersBernie SandersMeghan McCain to Amy Klobuchar: Leave my father ‘out of presidential politics’ Will top 2020 Democrats make ending war in Afghanistan a defining issue or an afterthought? Nevada emerges as wild card in 2020 Democratic race MORE (I-Vt.).

Biden’s appeal is simple: He bills himself as the best candidate to beat President TrumpDonald John TrumpCitizenship and Immigration Services union blasts Trump’s pick to head agency Texas secretary of state resigns after botched voter purge Trump hits Biden for 1994 crime bill support MORE, in part because of his roots in Scranton, Pa., and his cultural empathy for voters in the Rust Belt and Upper Midwest.

Trump has attacked Biden on Twitter as “Sleepy Joe.” But those attacks have boosted Biden’s cachet among Democrats, who see them as proof that the president fears him.

Biden’s appeal to nonwhite voters is, so far, stronger than anyone else in the field — in part, perhaps, a tribute to his loyal service to former President Obama.

Biden’s critics on the left insist his standing is falsely inflated right now and that he will fall to earth as his past record on everything from criminal justice to credit card companies becomes more widely known.

The 76-year-old former vice president has also had some verbal stumbles, as when he briefly referred to the late Margaret Thatcher, rather than Theresa MayTheresa Mary MayBrexit Party set to win most UK seats in EU elections Euroskeptics, Greens gain in EU elections as centrist parties lose ground The UK is one step closer to crashing out of Europe MORE, as the prime minister of the United Kingdom.

Overall, however, it’s clear Biden is the front-runner.

Previous ranking, Feb. 19: 2

2. Sen. Bernie Sanders (I-Vt.)

The Vermont Independent has held on to his position as the main standard-bearer of the left, despite facing increasing competition from Sen. Elizabeth WarrenElizabeth Ann WarrenWill top 2020 Democrats make ending war in Afghanistan a defining issue or an afterthought? Nevada emerges as wild card in 2020 Democratic race 2020 Dems join together for video marking Memorial Day MORE (D-Mass.).

Love him or hate him, Sanders is consistent. He is committed to the same democratic socialist ideals he has espoused for decades, he is as acerbic as ever about the media’s tendency to focus on personality over policies and many of his supporters display an intense devotion to him.

Sanders also has enormous resources. His campaign raised $18.2 million in the 41 days between his launch and the end of the first quarter. 

But can he recapture the same kind of magic that powered his 2016 campaign against eventual nominee Hillary ClintonHillary Diane Rodham ClintonClintons march in Memorial Day parade Nevada emerges as wild card in 2020 Democratic race Tester will endorse a 2020 candidate ‘in the next week’ MORE

The recent Monmouth University poll, conducted May 16–20, indicated support for him had declined by 5 points since the month before.

To win, Sanders needs the left to coalesce behind him. Warren’s rise suggests the opposite is happening.

Previous ranking: 3

3. Sen. Elizabeth Warren (D-Mass)

Warren is enjoying real momentum. In polls, she has broken out of the pack to become the clear No. 3.

Warren’s skill as a campaigner is evident in warmly received stump appearances. 

Her campaign has also shown a deft touch for social media and popular culture. In a video posted on Twitter, she discussed “Game of Thrones” with progressive icon Rep. Alexandria Ocasio-CortezAlexandria Ocasio-CortezOcasio-Cortez hits NYT over story on Hope Hicks: It’s framed ‘as some Lifetime drama’ GOP amps up efforts to recruit women candidates Ocasio-Cortez, progressives trash ‘antisemitic’ Politico illustration of Bernie Sanders MORE (D-N.Y.). In another tweet, she responded to comedian Ashley Nicole Black’s request for a plan to fix her love life.

Those flippant moments work because no-one doubts Warren’s intellect — she is a former Harvard Law School professor — or her policy chops. 

Warren has rolled out policies on a broad range of issues, which she is able to explain with specificity and accessibility. Her campaign has underlined this strength, selling merchandise with the slogan, “Warren has a plan for that.”

Like Sanders, Warren is vulnerable to the suggestion that her left-leaning beliefs make her less electable than other front-line candidates. The memory of her shaky handling of the question of her Native American heritage has not disappeared.

For all that, though, Warren is snapping at Sanders’s heels. If she were to supplant him as the leading progressive candidate, the landscape of the race would shift.

Previous ranking: 5

4. Sen. Kamala HarrisKamala Devi HarrisTrump hits Biden for 1994 crime bill support Will top 2020 Democrats make ending war in Afghanistan a defining issue or an afterthought? Nevada emerges as wild card in 2020 Democratic race MORE (D-Calif.)

Harris topped The Hill’s rankings in February. 

At the time, she had been boosted by a huge launch rally in Oakland, a sense that she brought more charisma to the race than any other candidate — and the fact that Biden had not yet declared.

Since then Harris’s fortunes have stagnated.

One persistent criticism is that she is too prone to caution. Her propensity to say she is willing to “have a conversation” about certain hot-button issues has been an inviting target for her skeptics.

Harris has also clarified or shifted her positions on several issues, such as whether her vision for “Medicare for All” involves the outright elimination of private insurance or whether police shootings should be investigated by independent prosecutors rather than local district attorneys.

Harris, the top-performing black candidate in the race, is so far receiving adequate but not outstanding support from nonwhite voters.

It’s far too early to count Harris out, but she needs some big moments that could push her closer to the very top of the pack.

Previous ranking: 1

5. South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegWill top 2020 Democrats make ending war in Afghanistan a defining issue or an afterthought? 2020 Dems join together for video marking Memorial Day Buttigieg campaign pushing wealthy supporters to keep up fundraising momentum: report MORE (D)

A Buttigieg Boomlet has propelled the 37-year-old mayor from near-obscurity to the higher tiers of the field. Can he go any further?

Buttigieg has embarked on an exhaustive round of media appearances, which have showcased his chief assets: likability, an ease and clarity before the cameras, and a center-left appeal to comity and cooperation.

But there are real doubts about Buttigieg’s ability to appeal beyond the upscale whites who form the main pillar of his support. Some racially-tinged controversies during his tenure in South Bend could further hamper his appeal to non-white voters.

Previous ranking: N/A

6. Former Rep. Beto O’Rourke (D-Texas)

O’Rourke is already seeking to reboot his campaign, appearing at a CNN town hall and on ABC’s “The View” and expressing regret for telling Vanity Fair that he was “born” to run for the presidency.

The effort comes after the initial hype over O’Rourke fell flat. 

The kind of retail campaigning that helped him in his Senate bid against Sen. Ted CruzRafael (Ted) Edward CruzOn The Money: Conservative blocks disaster relief bill | Trade high on agenda as Trump heads to Japan | Boeing reportedly faces SEC probe over 737 Max | Study finds CEO pay rising twice as fast as worker pay Conservative blocks House passage of disaster relief bill The Hill’s Morning Report — After contentious week, Trump heads for Japan MORE (R-Texas) last fall has not broken through this time. Nor has O’Rourke enjoyed the same kind of viral moment as he did in the Senate race, when his defense of NFL players protesting racial injustice became a sensation.

O’Rourke could come back, but he is not an especially strong debater and he faces the possibility that Buttigieg — whose appeal is demographically similar — may have stolen his thunder.

Previous ranking: 4

7. Sen. Cory BookerCory Anthony BookerNevada emerges as wild card in 2020 Democratic race 2020 Dems join together for video marking Memorial Day 2020 Democrats jockey over surging college costs MORE (D-N.J.)

Booker has struggled to find a place for himself in the crowded primary field. 

Having started his campaign talking about the transformative power of “radical love,” he has more recently sharpened his appeal — and his willingness to attack others. 

He has taken a strong stance on some issues, including the protection of abortion rights. 

But it’s not quite clear what the rationale for a Booker candidacy — or a Booker presidency — actually is.

Previous ranking: 6

8. Sen. Amy KlobucharAmy Jean KlobucharMeghan McCain to Amy Klobuchar: Leave my father ‘out of presidential politics’ 2020 Democrats jockey over surging college costs Democratic senator says McCain listed off names of dictators during Trump inaugural MORE (D-Minn.)

Klobuchar’s bid is predicated on the idea that Democrats are willing to choose a centrist from the heartlands as the best candidate to take on Trump.

She is a lot more circumspect than her more progressive rivals when it comes to issues such as the Green New Deal and Medicare for All. She has referred to herself as “Heartland Amy” and she, like Buttigieg, has done a Fox News town hall.

Klobuchar’s appeal does make her distinctive to some degree. But Biden’s dominance among centrist voters seriously curtails Klobuchar’s room to run.

Previous ranking: 7

9. Former Secretary of Housing and Urban Development Julián Castro

Castro got off to a slow start in his campaign and usually polls in the low single digits. But that’s better than some better-known candidates, including Sen. Kirsten GillibrandKirsten Elizabeth GillibrandLawmakers, Trump agencies set for clash over chemicals in water 2020 Dems join together for video marking Memorial Day Democratic groups gear up to use abortion rights as attack on GOP in 2020 MORE (D-N.Y.), who has failed to register at all in several recent surveys.

Castro has made opposition to Trump’s immigration policies one of his signature issues. He has also sought to play up his connection to Obama, in whose Cabinet he served.

Will that take him far? Probably not. But a respectable performance in the field could put him on someone’s shortlist for vice president.

Previous ranking: N/A

10. Businessman Andrew YangAndrew Yang2020 Democrats jockey over surging college costs Whip list: Who’s clinched a spot in the 2020 Democratic debates Klobuchar to roll out policy priorities for farmers in Iowa MORE

Yang, a rank outsider, has at least nurtured his own small band of supporters — the self-proclaimed Yang Gang.

Yang has an idiosyncratic approach, for sure — boosting his profile by appearing on well-known podcasts rather then cable news, for example.

He has bemoaned the power of big tech companies. He has suggested a new value-added tax on corporations, with the proceeds dispensed as a universal basic income.

It is virtually inconceivable that Yang will be the nominee. But he has at least made some kind of imprint on a race where many others have barely been noticed.

Previous ranking: N/A

Other candidates:

Sen. Michael BennetMichael Farrand BennetWhip list: Who’s clinched a spot in the 2020 Democratic debates DNC boss says candidates to be involved in debate lottery Overnight Energy: Democrats ask if EPA chief misled on vehicle emissions | Dem senators want NBC debate focused on climate change | 2020 hopeful John Delaney unveils T climate plan MORE (D-Colo.), Montana Gov. Steve BullockSteve BullockAll the states taking up new abortion laws in 2019 Tester will endorse a 2020 candidate ‘in the next week’ Whip list: Who’s clinched a spot in the 2020 Democratic debates MORE (D), New York City Mayor Bill de Blasio (D), former Rep. John DelaneyJohn Kevin Delaney2020 Democrats jockey over surging college costs Whip list: Who’s clinched a spot in the 2020 Democratic debates 2020 Democrats target federal ban on abortion funding MORE (D-Md.), Rep. Tulsi GabbardTulsi GabbardWill top 2020 Democrats make ending war in Afghanistan a defining issue or an afterthought? 2020 Dems join together for video marking Memorial Day Democratic candidates should counter Trump’s foreign policy MORE (D-Hawaii), Sen. Kirsten Gillibrand (D-N.Y.), former Sen. Mike Gravel (D-Alaska), former Colorado Gov. John HickenlooperJohn Wright Hickenlooper2020 Democrats jockey over surging college costs Whip list: Who’s clinched a spot in the 2020 Democratic debates The Hill’s Morning Report – Trump says no legislation until Dems end probes MORE (D), Washington Gov. Jay InsleeJay Robert InsleeDemocratic candidates should counter Trump’s foreign policy Whip list: Who’s clinched a spot in the 2020 Democratic debates Overnight Energy: Democrats push EPA to collect 4K in ‘excessive’ Pruitt travel expenses | Greens angered over new rules for rocket fuel chemical | Inslee to join youth climate strikers in Las Vegas MORE (D), Miramar, Fla., Mayor Wayne MessamWayne Martin MessamWhip list: Who’s clinched a spot in the 2020 Democratic debates Biden retains large lead over Sanders, other 2020 Dems in new Hill-HarrisX poll Momentum builds behind push to pass laws enshrining abortion rights MORE (D), Rep. Seth MoultonSeth Wilbur MoultonNevada emerges as wild card in 2020 Democratic race 2020 Dems join together for video marking Memorial Day Democratic candidates should counter Trump’s foreign policy MORE (D-Mass.), Rep. Tim RyanTimothy (Tim) John Ryan2020 Democrats jockey over surging college costs Whip list: Who’s clinched a spot in the 2020 Democratic debates CNN’s O’Rourke town hall finishes behind Fox News, MSNBC MORE (D-Ohio), Rep. Eric SwalwellEric Michael Swalwell2020 Democrats jockey over surging college costs Whip list: Who’s clinched a spot in the 2020 Democratic debates House Intelligence enjoys breakthrough with Justice Department MORE (D-Calif.), author Marianne WilliamsonMarianne WilliamsonWhip list: Who’s clinched a spot in the 2020 Democratic debates 2020 Democrats target federal ban on abortion funding DNC boss says candidates to be involved in debate lottery MORE.

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